The present invention relates to electric utility boxes that house electrical devices.
An electrical utility box is typically a rectangular, open-faced box mounted in a wall. It serves to house an electrical device, such as an electrical receptacle or switch or a GFI (ground fault interrupter). Electrical wiring, such as a flexible cable and wiring through rigid conduit, is routed into the utility box via openings in the box walls. The wiring is connected to the electrical device in the box.
The present invention is an electrical utility box configured to contain an electrical device. In accordance with a principal feature of the invention, the box comprises a bottom wall, two opposing side walls, first and second opposing end walls, a mounting boss and a shield structure. The mounting boss has a bore configured to receive a fastener that fastens the electrical device to the box. The shield structure is configured to block an uninsulated wire from contacting a protruding portion of the fastener that protrudes from an open lower end of the bore.
In a preferred embodiment of the invention, the shield structure includes a pair of opposed shielding surfaces. The shielding surfaces are located adjacent to an open lower end of the bore, spaced from each other with reference to the protruding portion of the fastener so as to receive the fastener closely between the shielding surfaces. An additional shielding surface, below the pair of shielding surfaces, prevents the fastener from protruding downward beyond the pair of shielding surfaces. The shield structure is connected directly to a knockout on the first end wall, so that the shield structure is removed with the knockout when the knockout is removed.
In accordance with another principal feature of the present invention, the mounting boss projects from one side surface of the first end wall. A slot along an opposite side surface of the first end wall extends downward from a top edge of the box. The slot is configured to receive a second fastener that fastens the cover over the electrical device in the box. The bore and the slot are preferably centered on axes that are equidistant from the side walls
Another principal feature is a flexible cable clamp. The box has a cable opening partially defined by the first end wall and partially defined by the bottom wall. An edge of the cable opening is defined by a ridge along the bottom wall. The clamp projects across the cable opening and has a free end configured to apply a clamping force to hold a cable against the ridge. Preferably, the second end wall has a knockout, opposing the clamp on the first end wall.